The Gasman Hacker
by Sherlock Emrys
Summary: A story based on one of the 'Unseen Stories' from canon, updated for the BBC series. No slash. Just a mystery and Sherlock being awesome.  A series of mysterious deaths take place in mines across the country,all of gas poisoning. NOW COMPLETE
1. Chapter 1

**AN: Okay, so this is a story based on one of the 'Unseen Stories' mentioned in the original series. I decided to write this because, well, the idea of a 'notorious canary trainer' appealed to me. I subsequently decided to be lazy and use Updated!Sherlock, as owned by The Moff and the Beeb, because I find it easier to write for. My first lengthy fanfic for this series, which given that I still haven't watched a single complete episode, was a terrible idea. And no, it no longer has much to do with canaries- although it won't take long to spot the link.**

PART 1

We begin with a quote from Arthur Conan Doyle himself: "In the year of '95 a curious and incongruous series of cases had engaged his attention… down to the arrest of Wilson, the notorious canary trainer, which removed a plague-spot from the East End of London." What follows is but one of these cases, namely that of Wilson, updated for the new and much loved Sherlock in the 21st Century.

The Gasman Hacker

Sherlock stamped about the flat in his characteristic bad temper. John Watson sat in an armchair, drinking a mug of thankfully pollutant-free tea (Sherlock had a very nasty habit of contaminating the kettle, teabags, teapot, milk and occasionally the water supply, leading John to seek refuge in Mrs Hudson's rooms for tea-ingredients) and doing some research on the computer. He nodded and said 'Yes' occasionally when it seemed appropriate, but otherwise allowed Sherlock to rant on his latest case uninterrupted. He was just contemplating a mid-afternoon biscuit when Sherlock intruded on his peaceful ignorance.

'-so you'll have to tell Mycroft that I'm not going to, and you- are you even listening, John?'

'Mmhm. Yes, Sherlock.' John took another sip of tea and decided against the biscuit.

'John, so help me I'll kick you out. You're worse than the skull, at least he listens.'

'Uhhuh.'

Sherlock rolled his eyes and threw himself onto the sofa.

John's phone beeped. A text. He checked it:

We've got a case. We are going down to the yard. Get ready now. –SH

John looked up.

'Sherlock, I'm sitting next to you, for pity's sake.'

'You were ignoring me.'

Without another word, the consulting detective pulled on his coat and scarf and swished out of the flat.

At the Yard, they were met by an exasperated looking Lestrade.

'Sherlock, if you do this again I'll-'

'You'll what? Get rid of the person doing all your work for you?'

And with that, Sherlock swept past him and into his office. John and Lestrade followed.

'What was he doing?' asked John in an undertone.

'The bloody idiot keeps turning up before we ask him to. It's like he i knows /i we've given up.'

'He's probably getting tip-offs from Mycroft.'

'Ah! John, come over here. Look at these case reports,' Sherlock interrupted. John walked around the edge of Lestrade's desk and glanced at the case files split-screened across the three monitors. Lestrade spluttered ineffectively for a moment before giving up.

'What about them?'

'They're all the cases of suspicious deaths in the mining industry for the last 3 months.'

'So?'

'So, some of them are connected. I've been meaning to tell the Yard for a while.'

'So why haven't you?' Lestrade broke in, angrily.

'Been busy. Anyway, you can't expect me to do all your work for you.'

Lestrade ground his teeth. 'Someday, Sherlock Holmes, you are going to be arrested for perverting the course of justice, perjury, laziness and any other damn charge I can make stick.'

'Laziness, to the best of my extremely detailed and accurate knowledge, is not in and of itself an offence under law, Lestrade. Oh for goodness sake, are the police really this imbecilic? We can obviously eliminate all those deaths that don't fit the pattern- that's this one with the mines supervisor, she was killed by her husband, it's obvious Lestrade- and these two, the mine workers, that was a suicide pact- do I have to do everything around here?- leaving these twelve.'

'I'm not even going to ask how you knew.'

'Good. Your mind might combust. Just get the husband of that supervisor in the Drrwg Gwelly coal mines and then release the suspect in the Abernethy case.'

Grumbling slightly under his breath, Lestrade sent off a text presumably issuing instructions.

'I want your evidence.'

'Later. Now, look. What's left? These twelve. All dead in similar circumstances. Died of carbon monoxide, carbon dioxide, methane or other gas poisoning. Found with fully functional gas detection devices, so no clues as to why they were poisoned by the gas. No clues as to how or why they died other than the cause of death. The first one was three months ago, how have the police taken this long?'

'We were busy, in case you didn't notice, with solving every crime in England,' Lestrade snapped. 'We don't all have the same free time you do.'

'Excuses, excuses. I was busy too, solving all the crimes you gave up on- which is most of them.'

John stepped in before the argument could escalate.

'But how are they linked otherwise? Could be a coincidence.'

'Twelve men, John,' Sherlock said. 'Please don't be a complete idiot. Twelve men decide to commit suicide, or twelve murderers decide to use the same method, within the space of three months?'

'Okay, so it was murder…'

'How do you know?'

'Is there another option?'

'Easy. They were all members of a gang and fulfilled a suicide pact. They were all members of an amateur electronics society and fiddled with the detectors, breaking them and causing their deaths. They were-'

'Alright, I get the message. So you don't think it's murder.'

'Of course I think it's murder John, keep up.'

'So why did-'

'Keep an open mind, John. There are lots of other options.'

'…Fine. Okay, fine.'

Sherlock turned back to Lestrade.

'So they're all connected. Why?'

'Could be a grudge against the mining company?' Lestrade suggested.

'Nope, they're from three different companies, six different mines. Not local, not a company grudge.'


	2. Chapter 2

**AN: Somehow this chunk got lopped off the end of the last chapter, sorry about that. Anyway, so I'm sorry for the slow update- I did warn you! Actually, I didn't. Sorry. Here's a warning: I hardly EVER update my stories.**

**A huge thank you for ALL the faves and follows. It means a huge amount that people read this :D Here's another chapter. Hopefully I'll be faster next time, now it's the holidays. Also, Sherlock and John are not totally in character- it's been so long since I watched _Sherlock_ I think it's slipping. I am really sorry, I did try. I'll keep trying, and hopefully watch more _Sherlock_ to get better at them.**

'Personal ties?'

'None as far as we can make out,' Lestrade admitted. 'But we're working on it.'

'Don't bother, there won't be any,' Sherlock muttered.

John had a thought.

'Union, what mining union do they belong to?'

'I… hang on,' Lestrade said, scanning the data. Sherlock was ahead of him.

'Look, they're all registered with the same union- UUKM. I wonder…'

'Connection?'

'Could be.'

John sat back as Sherlock and Lestrade bandied theories. He just knew that the fact that he had found the link would be utterly ignored by Sherlock, Lestrade, and indeed everyone else at the Yard.

**AN: Here's the ACTUAL chapter.**

**II**

'So, they all belong to the same workers union. What could be a motive for assassination within that?'

'Wasn't a grudge against the union,' Sherlock responded instantly, 'Could be a group that met through the union though.'

'How do you know it wasn't a grudge against the union?' John interjected.

'If it was, then they'd strike at a union meeting or somewhere they could get them all at once. Even if they couldn't wait, they'd eliminate all the workers from one mine first. The deaths have been in no order, up and down the country.'

'So how does the union connect them?'

'Maybe they were all members of a society that met through the union. Links back to our 'suicide pact' theory.'

'Cult?'

'Could be.'

'Look,' Lestrade burst in, 'I'll get right on these theories, check the union records, talk to other union members. But please, Sherlock,' and his voice took on a note of extreme frustration, 'get out of my desk.'

* * *

><p>It was two days later. Sherlock had utterly ignored the case, dismissing it as 'boring' when John dared to ask. John tried to avoid Sherlock anyway. He'd taken to shooting the walls again.<p>

In a rare moment of peace, John was sipping tea and reading a newspaper whilst Sherlock played the violin. John had to admit that he was actually very good, when not trying to cause ear-bleeds and headaches. It also sounded a lot better at times not between midnight and 7am.

Sherlock's phone rang, breaking off Mozart's Requiem Mass. **{1}**

'What is it, Lestrade?' he answered boredly. Suddenly, Sherlock shot upright, making John spill tea all over himself. 'You what? Are you sure?... Well yes, OK, but still… Because the police are imbeciles, that's how! I'll be there in five.' He hung up and grabbed his coat. John, who had just managed to clean up the last coffee spill, was knocked sideways by Sherlock's passing and the coffee went all over the chair.

'For pity's sake, Sherlock…' he began, but he was cut off.

'John, you're coming to Scotland Yard. The police are being imbeciles again.'

'What is it this time?' John enquired as he struggled into his coat.

'Idiots have messed up my case by finding evidence they say contradicts my theory. The cheek of it. They've made a stupid mistake, I just know it.'

'Did it occur to you,' John called down the stairs as he hurried out of the flat after Sherlock, 'that you might have made the mistake?'

Sherlock's head reappeared around the corner. 'Don't be ridiculous, John.'

* * *

><p>The Yard was bustling. Ignoring the odd and occasionally hostile looks, the pair made their way through the building. Sherlock barged straight into Lestrade's office, while John knocked half-heartedly at the open door. He wasn't sure why.<p>

As it happened, Lestrade was away from his office for something. By the time he returned, Sherlock had gone through his case files and absently solved three cold cases and a GBH/manslaughter case. He was in the middle of explaining his reasoning to John when Lestrade returned, stopped short, shook his head and walked into his office.

'Why do you smell of coffee?' he remarked to John in passing.

'Sherlock.'

'Oh. Oh, uh, right.'

'I don't know what you're thinking, but it's almost certainly wrong.'

'John,' remarked Sherlock, 'managed to throw coffee over himself when you called. He maintains that it was my fault.'

'It was your fault.'

'No it wasn't. You were stupid to be holding a cup of hot liquid at the time.'

'Whatever you're thinking, it's still wrong,' John informed Lestrade.

'Uh, anyway,' Lestrade said, 'the case. We've had another death. Same COD, same everything.'

'And?' prompted John.

'And,' Lestrade continued doggedly in the face of Sherlock's sulk, 'it disproves our theory on the unions. This victim belonged to the UKCM. Different union.'

'Could be a coincidence.'

'Really?'

'… No. Not really.'

'Glad we see eye-to-eye on that.'

'But,' Sherlock continued in a burst of energy, 'that doesn't mean I was wrong. Murderer could have made a mistake. Miner could have been thinking about a union transfer. Maybe the murderer just decided to branch out.'

'No evidence to support that.'

'Or,' John interposed, 'You were wrong.'

'Or maybe I was wrong. No, no, I don't do wrong. Funny little brains you have, can't realize that some of us don't make mistakes.'

'Just accept it and move on, Sherlock. So, what else do we have?'

John moved around Lestrade's desk to see his screen. The details of the dead man were scrolling up it.

'I can't see a correlation,' admitted Lestrade. 'Neither can anyone else. Now would be a really good time for you to have one of your moments of genius, Sherlock.'

Sherlock was staring at the computer screen, his fingertips steepled beneath his chin. His earlier tantrum was forgotten and he was solely fixed upon the mystery.

'What could make thirteen men walk into gas? Why would they do that?' he said softly. 'There's something… why would they go willingly? No struggle, but no reason to believe it was suicide… so why? Unless…'

John and Lestrade held their breath. Sherlock had that look in his eye, the 'I'm cleverer than you' look.

'What don't we see? What would we not question?... They knew that the gas was there… didn't they? The detectors were working perfectly…' He sat up. 'Oh, tell me you didn't… Lestrade! Tell me you tested all the gas detectors!'

'Of course we did. We aren't as stupid as you make us look, you know.'

'Who tested them?'

'I-'

'Oh, for goodness sake! You did test them yourself, didn't you?'

Lestrade recovered. 'Look, Sherlock, we don't have that kind of budget. We outsource.'

'So who did you outsource to?' Sherlock was yelling now.

'The manufacturers, of course. They know how to work the things-'

But Sherlock was gone. John gave an apologetic smile to Lestrade and followed, pelting down the corridor behind him. Lestrade was left alone in his office. After a moment, he sat down at his desk, slightly shellshocked. After another moment, he gave the matter full consideration and summed up his response in one word.

Suffice to say it was unprintable.

* * *

><p><strong>{1}<strong> It's an in-joke. Don't worry. Why Mozart's Requiem Mass? You'll have to ask a friend. I just thought I'd throw it in there.

**AN: Ok, here you go! I'll try and have another chapter up within a week, but it probably won't happen since I am incurably lazy.**


	3. Chapter 3

**AN: Wow, another update! I'm on a roll!**

**Okay, this one's pretty long but I couldn't find a place to stop it.**

**Incidentally, I shouldn't think anyone's under any delusions on the topic, but if I owned Sherlock I'd be running around London in a swishy coat solving crimes. So.**

**Also, I have researched this chapter, but unfortunatly I have absolutely _no clue_ how IPD's are manufactured and tested, so please take that as 'magical plot hole powers' of being right even though it isnt :)**

**III**

Sherlock and John were at that moment occupying themselves as they frequently did, ie sprinting through the streets of London hot on a trail. Or at least, Sherlock was. John was struggling to keep up and cursing inventively the day he chose to move in with the sociopathic Consulting Detective.

'Taxi!' Sherlock hollered, flagging down a passing cab. John shuddered slightly as he got in. He had had a mild phobia of taxi cabs ever since their first case.

The cab pulled away from the kerb and swung out into the seething London traffic.

'Where to?' enquired the cabbie.

'Liverpool Street station,' Sherlock responded idly. The cab set off.

'Sherlock,' John said when he had got his breath back (he was really far less fit than he should be, as a retired Army medic and a flatmate of Sherlock he should be in the peak of physical fitness) 'Where exactly are we going?'

'Oh come on John, surely it's obvious.'

'The only thing that feels obvious right now is that I'm never going to get to finish that coffee.'

Sherlock sighed. 'Come on, John! Why would these men, who we can assume had no death wish and were not coerced, walk into a patch of deadly gas?'

'Well, I can't…'

'Use your imagination. Think hypothetically. The only reason for someone to walk into a death trap is?'

'That they had no other choice.'

'Or?'

'They didn't…' John felt frustrated. He hated it when Sherlock made him do his thinking for him. Especially when Sherlock already knew the answer and could have simply told him. Suddenly, light dawned. 'Unless they didn't know it was there!'

Sherlock clapped his hands together. 'Well done, John. Precisely. They did not know that there was any danger.'

John felt a headache coming on. 'How is that possible? The gas detectors were perfectly functional.'

'Yes. And here you come to my second point. How do we know that they were functional?'

'They were tested.'

'By whom, John?' Sherlock said impatiently.

'By the… oh.' John stopped.

'Precisely. The only people with the power to have tampered with them in the first place. The manufacturers! And Lestrade sent them straight back where, I have no doubt, the perpetrators immediately fixed them to hide all evidence of their crimes.'

They sat in silence for a moment.

'So where are we going?'

Sherlock sighed. 'Sometimes, John, I despair of you. We are going to see the manufacturers, of course. The firm is called Erik and Moore gas detectors. Erik and Moore are presumably the senior partners and therefore under most suspicion. The firm is based in Essex, so we are going to catch the,' he consulted his watch, '3.45 train to Ipswich from London Liverpool Street. Questions?'

* * *

><p>An hour later, Sherlock and John were standing outside a grubby workshop on an industrial estate. 'Senior Partners', it turned out, was far more glorified than this dead-end dump intimated. Sherlock glanced up at the sign- 'Erik and Moore gas detection Ltd' and pushed open the door gingerly. It sagged slightly.<p>

A row of strip lights illuminated the gloom, revealing a bare concrete floor and mould. There was a desk propped up in one corner. Against all probability, it had wads of paper under all four legs.

Half the room, however, was taken up with a substantially more impressive sight. It was a glass chamber, completely sealed, with big red warning notices pasted over the side and a row of bio-suits hanging by the door. Inside, it was lit brightly by a brand-new light. A red LED over the door burned brightly, and a large warning notice proclaimed that the chamber was currently unsafe to enter. Inside stood a man in a sealed bio-hazard suit, holding a small cuboid which was flashing slightly. The man looked up, saw John and Sherlock and visibly jumped. He raised a hand- in greeting or warning, they couldn't tell- and made his way towards the door which, John saw, was designed like an airlock. There was a slight hiss, the light became green, and the door swung open. The man clumped out and without a word to John and Sherlock dumped the device on a workbench. He unzipped the bio-hazard suit and hung it on a peg.

'So, what do you want?' he asked gruffly. He had an Essex accent and a potbelly. He hardly looked like a master criminal. Then again, John reflected, nobody did. Aside from Mycroft. Who wasn't, so it didn't count. Unless being the British Government made you a criminal- which it probably should if the amount of tax he'd been paying was anything to go by.

John shook his head and returned to the present.

'I would like to meet Mr Erik and Mr Moore, the owners. Is that possible?' Sherlock was asking smoothly.

The man laughed. 'Yer looking at Mr Erik. Call me Will, s'friendlier. Kyle- Mr Moore- is around the back.' He raised his voice. 'OI! KYLE! Get yer ass in here, we got visitors!'

Footsteps sounded around the edge of the huge chamber. A dapper looking man emerged from around the corner. His dark hair was spiked slightly and he wore a ACDC T-Shirt. His converse shoes were battered but neatly cleaned. He was poor, but took pride in what he had. John shuddered. He was beginning to think like Sherlock.

'What can we do for you?' asked Moore. For some reason, John took a more or less instant dislike to him.

Sherlock stepped forwards. 'We're here to enquire about testing methods for gas detectors. There's been a spate of failures recently, as I'm sure you're aware, and we want to reassure people that there is no lapse in security or safety. Unfortunately, we aren't so familiar with the process and we'd hate to get it wrong.' He smiled tightly.

'Sure, no problem mate,' Erik responded, moving to pass them two bio-hazard suits. His partner held him back.

'Hang on a moment, Will.' His dark eyes inspected John and Sherlock. 'I'm sure you understand, gentlemen, but I'm going to need some identification from you two. Who do you work for?'

John began to panic slightly, but Sherlock simply reached into his coat and removed a laminated ID badge. 'I'm Simon Harris, I work for the PR arm of the United Kingdom Mining Union. Our members have been worried, obviously, so I'm just here to give them some reassurance. This is John Smith, he's my junior. Neither of us are hugely familiar with the process, so…'

Moore still looked suspicious, both of them and just generally suspicious (he had really shifty eyes) but he nodded and let his partner move on.

'So basically,' Erik told them enthusiastically, 'This is a giant gas chamber. If you were to be stuck in here without a suit, it could get really nasty. This is top-of-the range stuff, we have to conform to really strict guidelines here. You just pull on an airtight suit and stand in there with the detector you're testing. We can pump in variable amounts of all four dangerous gases we test for; whitedamp, blackdamp, firedamp and stinkdamp.'

Sherlock nodded like he knew what that meant. John was willing to bet he did, too.

'Kyle, can you run the gas for me?' Erik called. Moore nodded and went back behind the tank. Erik pulled on his suit again. 'Right, if you want to go around the back, Kyle will show you how the controls work. You need to operate the gas input from outside.' Erik keyed in a code with clumsy gloved fingers and the outer door slid open. He picked up the detector and entered the airlock. Behind him, the door slid closed and the light turned red.

'John Smith?' muttered John as they made their way around.

'Well, I didn't want to overload you too much. You might not have been able to remember a different first name and I don't want you giving us away.'

John rolled his eyes.

'Isn't that the most obviously fake name you could have picked?'

'It would be,' agreed Sherlock, 'If it wasn't for the fact that everyone knows that John Smith is an obvious fake name, and therefore wouldn't pick it as an alias, so therefore the only people using it are not using a fake name.'

'That was convoluted.'

'Welcome to the world of crime,' Sherlock muttered.

They rounded the corner to the other side of the chamber. Moore was standing at a bank of complex looking controls.

'Do you want an explanation of these?' he asked, looking up. He didn't look altogether friendly.

'If that's okay,' Sherlock responded.

'Right. These four here,' he indicated four large buttons, 'control which gas we pump in. These sliders control the amount. The first test I'm going to do is with Carbon Monoxide.' He slid the sliders down to the bottom again, then hit the big button labelled CO. Inside the chamber, a sign lit up with 'Carbon Monoxide' written on it. Erik gave a thumbs up from inside his suit and flicked a button on his detector.

'As I slide up the slider,' Moore continued, 'the quantity increases. Like so.' He raised it up. A readout in front of him showed the gas level inside the chamber. At present, it was a normal mix of Oxygen, Argon, Hydrogen, Helium, and Carbon Dioxide. Levels of CO were low but as Moore manipulated the controls it began to rise. The bar flashed from green to red at the exact moment that the device Erik held began to beep. Erik gave a thumbs up to Moore, who nodded and slid the slider back down.

'We don't actually empty out between tests,' he explained, 'but we do purge the chamber regularly. We clear it to a safe level of each gas before we begin the next one, so as to not contaminate the readings.'

Sherlock nodded. A light on the console blinked green.

'Ah, there we go. Next gas,' Moore commented. He pushed the button labelled CH4. The sign in the chamber winked out and was replaced by one reading 'METHANE'.

As before, the device beeped just as the bar turned from green to red.

'That colour change means Dangerous,' Moore explained. 'It's actually still a safe level, but it's high enough to be potentially dangerous. We have the boundaries so low because that gives people a chance to get to safety.'

John & Sherlock both nodded. John felt like this was the first thing he'd understood all day.

The testing continued. When all four gases (Carbon Monoxide, Carbon Dioxide, Methane and Nitrogen, as well as compounds of the four) had been tested, Erik made his way to the airlock and slammed his palm against a release button. Sherlock, John and Moore walked around to the other side of the tank.

'So, Mr Erik, what position do you hold in the company?' Sherlock enquired. He had produced a notebook, presumably for veracity's sake, and was taking notes.

'Well, Mr- Harris, wasn't it?' Erik checked. 'Right, Harris. Okay, well technically I'm a senior partner and co-CEO. Not that that means much! S'just me and Kyle here, so really I'm the program guy. I do all the software stuff on these. Kyle's the one who actually assembles them, although we do each others jobs sometimes if one of us is off sick or summin.'

'Alright, thank you, Mr Erik. And what would you say your position in the company was, Mr Moore?'

'Like he said, I'm a Senior Partner and all but I do the hardware. Works out quite nicely, really.'

'Okay, thank you,' Sherlock said, pocketing his notebook. 'I think that should be it. If we need anything else, we'll phone up, is that OK?'

'Sure, any time. D'you want anything before you go- tea, coffee?'

Sherlock shook his head. 'Sorry, we have to catch a train. Come on, John.' He turned and swept out. John gave an apologetic smile and shook hands with the two men before hurrying after him.

**AN: Incidentally, I'm from Essex. That's why I based it here. Also, trains from London Liverpool Street to my nearest station are 45 mins; I made it an hour to account for the fact that they are going further down the line and also travel time ect.**

**And if anyone wants to correct me on IPD testing methods, feel free. I could use the info.**


	4. Chapter 4

**AN: Hi everyone, I'm back! Thank you for all the faves and alerts, that means a lot! Sorry this chapter took a while. I'm lazy. **

**However, I have finally watched The Blind Banker and The Great Game (awesome) so this is hopefully a little bit more in character. I can't wait for the new series :D So, here you go.**

IV

The train clattered over the tracks, rattling and swaying from side to side. Sherlock was sitting sprawled across two seats in the almost empty train, staring out of the window. John was engrossed in a newspaper. He studiously ignored Sherlock, who returned the favour by sinking deeper into his brown study.

'John,' Sherlock spoke suddenly. John laid aside his paper and waited.

'Yes?'

'How do you feel about housebreaking?'

'Wouldn't be the first time, would it, Sherlock? As long as you let me in this time, I don't mind.'

'Good. Ah, here's our stop.'

The train had drawn up at the next station on the line, Shenfield.

'No, it isn't.'

'Yes it is, John. Come on.'

Sighing, John followed Sherlock out of the carriage and onto the windy station platform. The train clattered off into the distance, and with it went any hopes he might have had of going home that day.

'So why are we not going back to London today, Sherlock?' he asked. The tall figure of his companion was already headed off down the platform, his coat flapping in the wind.

'I already told you. We're breaking in,' he called back to John. The doctor swore under his breath and hurried after him.

* * *

><p>Night had drawn a little closer by the time they had returned via a taxi. The shadows were long and dark blue. The sun had sunk close to the horizon and was shining directly in John's eyes as he made his way around the side of the building. He stepped cautiously through the thickets of brambles and nettles that had pushed their way through the concrete, which had shattered and chipped beneath him. The surface was uneven, chunks of concrete poking up at all angles, interlaced with shattered glass, lager cans and bits of junk. John tried to make his way through quietly, but his clothes caught on the weeds and he stumbled over hidden obstacles in the undergrowth. His muttered curses were probably an instant tipoff to anyone who might be listening.<p>

Finally, he saw in the fading light a tattered, battered old door, the paint peeling and wood flaking but the big bolts and padlock shining like new. They probably were. John tried it without much hope; it was locked.

* * *

><p>Sherlock snuck around the front of the building. They had approached it obliquely, John heading to the back and he to the front. He ducked down and crawled under a window, staying close to the crumbling wall so as to be invisible from inside. He kept his back against the wall as he inched around to the door. Finally, he reached it. Checking behind him at the deserted, rundown estate he tried the handle. Locked. He slid a lock pick out of a packet in his pocket and with a swift jiggle the lock was freed. He tried again. The door refused to open. He frowned- obviously bolted from inside. Interesting.<p>

He walked to the window again. Cautiously, he peered inside. The layers of accumulated grime made it impossible to see inside the building. He pressed his ear against the wall. He could just make out a faint sound- rustling, squeaks, a few thumps…

'Somebody's building something,' he breathed. He thought swiftly. The door was bolted and the place should have closed down hours ago. Whoever was building something in there was doing something illegal. Therefore, whoever was making the noise was the person building faulty gas detectors.

His fingers curled around the door handle, preparing to smash it open.

* * *

><p>John stared, frustrated, at the door. The padlock was brand new and would not budge. The bolts were rusted, but they were strong. They wouldn't snap or break. The only way to open this door would be the key.<p>

He slumped against the wall as he thought. This was typical of Sherlock, to just go swanning off like that. Leave John with the door that won't open, it'll keep him out of trouble. He almost gave the wall a thump, but stopped himself. That would just alert whoever was inside, potentially putting Sherlock in danger. If he wasn't in some already. The man could find trouble anywhere.

His phone beeped in his pocket. He pulled it out, surprised that he could still get signal out here. A text flashed up on the screen.

Where are you? –SH

Where you told me to be. -JW he texted back. Moments later, it beeped again.

Come here. –SH

Where's here? –JW

The front. Hurry. –SH

John put the phone back in his pocket and hurried around to the front of the building, ducking under windows and trying to walk quietly. He suspected that a herd of elephants could move quieter than he did.

Sherlock was waiting for him.

'You took your time,' he muttered.

'Yeah, well, I was busy doing what you asked me to do,' John retorted.

'Right, listen. Somebody is in there,' Sherlock said, pointing to the front of the building, 'and they are doing something illegal.'

'How do you know?'

'Oh wake up, John. The door is locked, but it's also bolted from the inside. That means whoever bolted it is still in there. So they bolted themselves in. They didn't want to be interrupted. Was it bolted on the inside this afternoon?'

'Well, no, but-'

'Right, so it's not normal business, and it's too late for normal work anyway. So they're doing something that they shouldn't be doing. We know that one of those two is tampering with the detectors-'

'Could be someone else who snuck in afterwards.'

'No, they would have locked up after themselves and for this person to lock themselves in there they'd need a key anyway. So it was one of them, they're the only people who have a key.'

'Okay, so either Erik or Moore is in there, tampering with a detector. So now what?'

'So now we break in, catch them in the act.'

John stared at the detective for a moment.

'You make that sound so straightforward.'

'Of course it's straightforward. Done it hundreds of times.'

'I really hope you're joking, but given your sense of humour…'

'Why would I be joking? Everyone knows how to break into places. Basic skill.'

'Maybe for you, Sherlock, but for most people that is not normal!'

'Keep your voice down, John, you'll alert them.'

'I'm calling the police.' John's hand was halfway to his pocket before Sherlock grabbed it.

'We don't have time for the police, John. We have to get in there now.'

He released John's hand, and stood up.

'Ready?'

'No.'

'Good.'

With that, Sherlock kicked open the door. It was slightly stiff and took two kicks to open, but splintered apart to create a hole big enough for the two men to rush through.

The interior was just as gloomy as before. Hunched over the workbench in the corner was a shadowy figure. John's eyes were slow to adjust to the darkness and at first he could not make out the figure. However, the man saw them, kicking aside the fragments of the door. He gave a garbled shout and stood up, unsure and panicked. He rushed towards them, but Sherlock was ready and met him halfway. The gloomy half light of the workshop revealed the pale, sweaty features of Kyle Moore. He had his hands around Sherlock's throat, trying to strangle him, but Sherlock was already peeling his hands off his neck and punching him hard in the face. Moore gasped and staggered back, his nose broken.

Sherlock straightened, rubbing his throat. Moore crouched like an animal, staring at them. Suddenly he gave a mad howl and rushed forwards again, but Sherlock once again caught him a terrific blow on the jaw. He fell backwards, and his head cracked on the cold concrete.

'Sherlock! Are you alright?' John cried.

'Yes, yes, fine,' the detective muttered. He rubbed his throat again. 'Odd..'

'What?' John was already examining the man.

'It's odd. It doesn't make sense. I didn't think that it was Mo-'

'Sorry, Sherlock? What was that?' John straightened up. His friend's voice sounded like it had been choked off. Suddenly the meaning pierced through to his tired brain and he spun, drawing his pistol.

Sherlock was clawing at the hands around his neck as they choked the life out of him. John levelled the barrel and thumbed back the hammer, but the man jerked Sherlock in front of him and was using him as a shield even as he choked him. John dropped the gun and ran to him, trying to free Sherlock from his grasp. The light shone on his face, revealing Erik, the other engineer.

He punched him in the jaw and the man's arms weakened, allowing Sherlock to draw a deep breath, but he didn't let go. The three men wrestled with each other as they grappled for purchase, but John and Sherlock were strong enough combined to prise him off Sherlock and allow the detective to breath freely.

John punched Erik again and saw him sag. He relaxed slightly. Mistake. With one almighty shove, Erik pushed Sherlock backwards. Sherlock pin wheeled, his coat flying out behind him. He fell straight through the open door of the gas chamber, which was just behind him. In the fight, they had moved towards it. Sherlock shook his head and began to get up but the door swished shut in front of him. He swung around, pounding the door. John watched in horror as a red light flicked on over the door.

John was brought back to himself by Erik's punch. His jaw exploded with pain and he shook his head to clear his vision, launching himself back at the engineer. He aimed his fist squarely at the man's nose and the criminal fell backwards like a felled tree. John bent down and checked him quickly. Out for the count. No way was he waking up soon, but John wasn't taking chances and quickly hammered on his forehead with the butt of his pistol. He wouldn't wake up for a few hours.

John glanced up, suddenly remembering Sherlock, expecting to see him standing beside him. He wasn't there. John's gaze swung back to the tank. Sherlock was still pounding on the door. Why wasn't the release working?

John shot upright and sprinted around to the controls, a sick feeling settling in his stomach. Sure enough, even as he ran, he could see the panel lighting up. Carbon Monoxide. Methane. Carbon Dioxide. Nitrogen. All four were glowing gently, harbingers of death. He speeded up.

Sherlock was pounding on the release switch. He saw John knock out the man and redoubled his knocking. He could guess what would happen now.

A faint hissing told him that his fears were justified. He spun around, and saw distorted by the glass the face of Kyle Moore. His nose was broken and blood ran down his chin, but he was operating the levers with determination. The panels lit up and Sherlock turned back to the door, pressing the release button over and over. Nothing. He hoped John would hurry up.

John skidded to a halt, taking in the scene. He grabbed Moore and pulled him away from the control bank, but the wiry man fought back, smashing John's head against the wall. John saw the displays mounting, inching towards the red. Out of the corner of his eye, he saw Sherlock stagger. He fought with renewed desperation, his hand straining towards the button that would halt the gas and flood the chamber with fresh air. Moore's hands were at his throat and he was finding it hard to breath but he kept reaching for the button that would save Sherlock.

* * *

><p><strong>AN: Okay, so it's a little bit of a cliffhanger. Only not really. I mean, they're the main characters, of course they'll survive. But at least there was a little bit of drama, right?<strong>

**...Hmm. That logic also applies to The Great Game. But still.**


	5. Chapter 5

**Sorry this took a while, but I'm afraid my internet has been rather unpredictable lately. **

**Also, I know that in an earlier chapter I made a really very stupid error, by starting out with 'John drinking tea' and then 'John spilling coffee'. I actually realized it a few chapters back but I'm afraid that the thingy hasn't been letting me change it and I kept forgetting to put it in an AN. Another thing that I forgot to put in it 'Thanks for the alerts and faves' because they are wonderful things. Reviews are even better :hint:. **

**Here's the last chapter!**

V

Sherlock reeled, choking, inside the chamber. He was finding it more and more difficult to breathe, the deadly gases making his lungs burn. He slid down the wall, his vision blurring as his eyes began to close. He fought to stay conscious, knowing that if he let himself sleep he would never wake up. Through his distorted vision he could see John grappling with Moore on the other side of the glass, trying to get to the button to operate the vents. Sensible. He wasn't wasting time with the door control.

Sherlock heaved in one last breath and tried the door again. How could he have disabled the controls? Surely they would have a built in override. He punched the door release again and again but it wouldn't budge.

John struggled towards the button on the console, no longer caring about getting the man off him. Finally, his fingers touched the cool metal of the framework. He stretched his arm to breaking point, finally grazing the button with his fingertips.

Sherlock heard the click through the haze of gas, the whirr as the fans began to clear the chamber. He sucked in a great breath of clean, fresh air, collapsing in a heap by the door as he coughed so hard he thought his lungs might make it out through his throat.

Through the glass and the tears that filled his vision, he could see John struggling with Moore over by the controls. It looked like Moore was winning and he knew he should get up and help but he couldn't quite make his limbs move themselves yet.

John couldn't even see if he'd managed to get the button. He had pushed at it but he couldn't spare a glance for Sherlock right now because he was fighting Moore, who had transformed into a crazed psychopath. John had met enough of them to recognize this- Sherlock seemed to attract crazed psychos like flies to a piece of fruit.

John slammed a fist into the man's gut and saw him double over in pain, but Moore reached up and scratched his nails down the side of his face. John stumbled backwards and let out a few choice words that he saved for situations like this (or the times when Sherlock left severed limbs in awkward places).

Now that he was concentrating on Moore, rather than on saving Sherlock, John was able to swiftly incapacitate him via a knee to a particularly vulnerable area and a fist clobbering him on the back of his head. Moore crumpled to the floor and John stood up, breathing hard, and rubbed his face where the man's nails had raked across his cheek. Glancing over the panel of controls, he found a button labelled 'EMERGENCY OVERRIDE' and pressed it, on the basis that it had to do something and that something was quite possibly useful. The door clicked and swung open. John bent down and dragged Moore around to the front with him, then hauled Sherlock out of the chamber. Sherlock insisted- in a hoarse, almost inaudible voice- that this was unnecessary. John pointed out that Sherlock was currently incapable of supporting his own weight, at which Sherlock pointedly stood upright. John raised an eyebrow, and tried not to laugh when the chair that Sherlock was supporting himself on collapsed and Sherlock fell to the ground in a heap of chair and coat and consulting detective. John wasn't feeling all that good himself, but he managed to phone Lestrade and explain the whole bloody mess while Sherlock recovered his ability to stand and walk. Lestrade seemed not a little amused by John's description of Sherlock's incapacitation, and John surreptitiously shot a few minutes of video on his phone to illustrate the point. Sherlock, being Sherlock, noticed but that only added to the amusement value since he attempted to stride towards John to confiscate the phone, collapsed halfway and tripped over his own feet. He then pushed himself upright and demanded in a distinctly high pitched and rasping voice that John stop that. John suspected that his phone was going to need protection.

When the local police arrived, alerted by Scotland Yard, Sherlock was back to his usual insufferable self, despite sounding like he had a bad cold. He was able to direct them to the two suspects, who were currently out cold on the floor, and have them charged with assault, murder, conspiracy to commit murder and property damage. John then shepherded the detective back to the station, to take the next train up to London.

'So the two of them were working together?' John asked as they took their seats.

'Yes. They both worked separate aspects of the business and although they could have been working solo the attack against us proves that they were partners in crime.'

'But what kind of motive could they have?' John wondered. 'They didn't have a grudge against any affected people or companies…'

'It wasn't anything like that logical,' Sherlock responded. He pulled a phone out of his pocket and pushed a few buttons, turning the screen to show John a webpage. 'Kyle Moore was webmaster for this site, and Erik Wilson was an admin.'

'A _website_?' John said incredulously. He peered closer at the screen. 'It's about… pollution and things. About how the coal consumption in Britain is…' he trailed off.

'Precisely, John! They weren't targeting companies or individuals at all. They were targeting the industry!'

'Yes, well done Sherlock,' John said waspishly, 'but what I'm more concerned about is the fact that that appears to be my phone.'

Sherlock shrugged. 'My internet has been acting up lately.'

'How did you even get my phone?' John demanded as he made a grab for it.

'I picked your pocket, of course,' Sherlock said as he held the phone out of reach. He pressed a few more buttons. 'Done.' He threw the phone back to John, who wasn't expecting it and accidentally dropped it in his lap. John picked it up and checked through the files, fairly certain he knew what Sherlock had done. The consulting detective was looking slightly smug as he glanced out the window.

John found exactly what he expected to. Or rather, he didn't.

'It's too late, Sherlock,' he commented as he slid the phone into his pocket. 'I already sent that file on to Mycroft.'

The look on Sherlock's face was so unprecedented that John couldn't resist taking a sneaky photograph and sending that on too.

Needless to say, the video and photograph found their way around the Yard remarkably quickly, causing Sherlock to sulk for a week and refuse to help the police with any cases for another month.


End file.
